2003 年 10 巻 303 号 p. 86-92
Synthesis of CaCN2 from CaO with NH3 and CO was investigated. CaCO3 was formed below 700°C but CaCO3 was not formed above 750°C. The optimum temperature for synthesis of CaCN2 was 700-730°C and the maximum yield was about 38 mol%. Reaction (1) was estimated from materials balance for CaCN2 synthesis at CO concentration lower than 50 mol% : CaO + 2NH3 + CO→ CaCN2 + 2H2O + H2 (1). Similarly, reaction (2) was estimated at higher CO concentrations : 5CaO + 10NH3 + 7CO →5CaCN2 + 2CO2 + 8H2O + 7H2 (2). Increasing the CO concentration, CO would react with formed H2O to form CO2 and H2, which result in eq. (2). NH3/CO ratio of the feed not so much affected the CaCN2 yield and the optimum ratio is about 1.0. The changes in W/F less affected the conversion of NH3 and CO. The CaCN2 yield increased below 40g·h· mol-1 and the yield extraporated to zero W/F reached to 70 mol%. The CaCN2 yield was independent of the average diameter of the CaO granules at 600°C.